#define _CRT_SECURE_NO_WARNINGS	

bool isUnique(char* astr)
{
    int arr[128] = { 0 };
    int len = strlen(astr);
    for (int i = 0; i < len; i++)
        arr[astr[i]]++;
    for (int i = 97; i <= 122; i++)
    {
        if (arr[i] > 1)
            return false;
    }
    return true;
}